1. Field
The present disclosure relates generally to manufacturing and in particular, to a method and apparatus for manufacturing objects using laser sintering.
2. Background
Sintering is a process that may be used to make objects from powder. These objects include ceramic and/or metal objects. Sintering involves heating a material until the particles adhere to each other. With sintering, the material may be heated to a temperature that is below the melting point to provide for solid state sintering.
Laser sintering is a type of sintering in which a high power laser is used to fuse particles into a mass representing a three-dimensional object. With this type of manufacturing process, the laser selectively fuses powdered material by scanning cross-sections of powder in a bed. These cross-sections are scanned based on a three-dimensional description of the object or part. This description may be obtained from various sources such as, for example, a computer aided design file, scan data, or some other source.
After each cross-section is scanned, the bed is lowered and a new layer of material is applied on top of the scanned layer. The process is then repeated until the part is completed. Laser sintering may be useful for manufacturing prototype parts and/or limited or small numbers of parts. With currently used laser sintering machines, the powder used to create parts is often wasted during the build process. When a layer is scanned with the laser, the entire build layer is recoated with powder. At the end of the build job, some of this powder can be reclaimed and reused. However, a large amount of the powder is unusable and disposed of.
Further, with currently available laser sintering machines, scaling to create parts of larger sizes may be a function of the amount of powder. With a larger amount of powder, the amount of time needed to wait for the powder to cool down increases. Thus, with currently available machines, larger parts cannot be manufactured as quickly. Even further, with larger amounts of powder, differences in temperatures at different layers may result in parts that are warped or that do not meet tolerances.
Therefore, it would be advantageous to have a method and apparatus that overcome the problems as described above, as well as possibly other problems.